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Current Design and Construction Practices of Bridge Pile Foundations with Emphasis on Implementation of LRFD |
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| Authors: | Sherif S AbdelSalam Sri Sritharan Muhannad T Suleiman |
| Affiliation: | 1Graduate Student and Research Assistant, Dept. of Civil, Construction, and Environmental Engineering, Iowa State Univ., 405 Town Engineering, Ames, IA 50011-3232. E-mail: ssabdel@iastate.edu 2Wilson Engineering Professor and Associate Chair, Dept. of Civil, Construction and Environmental Engineering, Iowa State Univ., 376 Town Engineering, Ames, IA 50011-3232 (corresponding author). E-mail: sri@iastate.edu 3Assistant Professor, Dept. of Civil and Environmental Engineering, Lafayette College, 321 Acopian Engineering Center, Easton, PA 18042. E-mail: suleimam@lafayette.edu |
| Abstract: | The Federal Highway Administration (FHWA) mandated the use of the load and resistance factor design (LRFD) approach in the U.S. for all new bridges initiated after September 2007. This paper presents the bridge deep foundation practices established through a nationwide survey of more than 30 DOTs in 2008. Highlighted by this study are the benefits of the LRFD as well as how the flexibility of its usage is being exploited in design practice. The study collected information on current foundation practice, pile analysis and design, pile drivability, pile design verification, and quality control. Since this is the first nationwide study conducted on the LRFD topic following the FHWA mandate, the status on the implementation of LRFD for bridge foundation design was also examined. The study found that: (1) more than 50% of the responded DOTs are using the LRFD for pile design, while 30% are still in transition to the LRFD; and (2) about 30% of the DOTs, who use the LRFD for pile foundations, are using regionally calibrated resistance factors to reduce the foundation costs. |
| Keywords: | Load and resistance factor design Piles Bridge foundations Design Deep foundations Pile foundations |